Figure. Illustration of multispacer typing. Amplicons 1–4 result from PCRs on DNA obtained from 1 Rickettsia raoultii–infected Dermacentor reticulatus tick isolate; lanes 5–8 result from PCRs on 1 damaged isolate. PCRs amplifying dksA-xerC (lanes 1 and 5), mppA-purC (lanes 2 and 6), and rpmE-tRNA (lanes 3 and 7) intergenic spacers were performed as described (5). PCR amplifying the entire internal transcribed factor 2 (ITS2) locus of D. reticulatus tick (lanes 4 and 8) was involved in each PCR run as a positive control and for validation of D. reticulatus tick identity (the primers will be described elsewhere).The negative result of ITS2 PCR with the damaged isolates (lane 8) indicated that they are not D. reticulatus ticks. Lane M, DNA size marker (100-bp ladder). PCR products were directly sequenced in both directions with respective primers by an ABI PRISM DNA Sequencer (Applied Biosystems, Foster City, CA, USA). DNA Star package (DNA Star, Madison, WI, USA) and the tools offered by the National Center for Biotechnology Information (www.ncbi.nlm.nih.gov) were used for DNA search and analysis.